Structure and productivity in kermes oak shrublands ( Quercus coccifera L.)
Shrublands with kennes oak ( Quercus cσccifera L.) as dominant species play an important role in the nutrition of grazing animals during all seasons of the year. In this work the results are presented of a study and researchconceming the productive structure of kennes oak shrublands, the distribution of their available production in different heights from soil were investigated. The research was carried out at the villages of Pente Vryses and Lophiscos (Thessaloniki Prefecture) on an area of 545 ha, covered by herbage and woody vegetation. The experimental design was a system of double sampling with stratification. In the first phase aerial photographs, orthophotographs and topographical maps were used, on which the rangeland types were separated and delimited; the research area was estimated and stratified in four classes of 0-15%, 16-40%, 41 -70%, 71 -100%. That was followed by the design of ground sampling for the measurement of shrub cover (2nd phase). Apart frοm shrub cover, the structure of kennes oak shrublands and the available kennes oak shrublands production in three height classes of 0- 50 cm, 0-100 cm and 0-150 cm. The greatest change in the upper height class structure of these shrublands was observed on these plots when shrub cover was over 40%. The maximum quantity of total available production (herbaceous and shrubby) is produced by kennes oak shrublands of up to 15% coνer and 50 cm height. The distribution of the available shrub production followed a decreasing course in relation to shrubs height.
Forage production and quality of shrublands improved by mechanical means
Reduction of shrub cover in Mediterranean shrublands is considered as a method of optimizing forage and animal production. In this study, forage production and quality in cleared, slashed and not treated (control, 55% shrub cover) shrublands were compared dming the spring seasons of 1992, 1993 and 1994. The improvements were done in October 1991 and pastures remained ungrazed until spring of 1992. Clearing and slashing of shrub vegetation resulted in higher amounts of available herbaceous forage and useable browse; also both browse and herbs in the improved shrublands were easily accessible because of the open structure and the lower height of the sprouting shrubs. Grazing animals (sheep and goats) had a higher bite rate (bites/min) in the treated shrublands than in the control. Quality of the forage selected by animals was better (Ρ ≤ 0.05) in the treated shrublands than in the control; diets were significantly higher in crude protein content and more digestible than those in the control pasture but lower in neutral detergent fibre and lignin contents. It is concluded that reducing of woody vegetation in dense shrublands results in increased forage production (available herbage and useable browse) and improved forage conditions for small ruminants.
Effects of ΝΡ fertilisation on the nutritive value of herbaceous species
The various species of grasslands contribute to the herbage nutritive value in a different way. The combined ΝΡ fertilisation can improve this nutritive value substantially. The influence of ΝΡ fertilisation on the nutrient content of the main species was studied during 1989 and 1990 in a Chrysopogon gryllus -Dichanthium ischaemum grassland in Macedonia, Greece. The ferti1izer was applied at three leve1s: 0, 100N+100P and 200N+100P kg/Ha. lt was found that Ν,Ρ and Κ contents were increased more in grasses than in forbs.
Possibilities for reclamation of degraded chromium mines
Chromium exploitation workings produce poor in nutrients waste materials. One major problem in establishing a cover of vegetation οn them is the lack of major nutrients Ν, Ρ and Κ . However, there is an excessive mobility of plant nutrients, especially Ν, so that deficiency may occur within 2 to 3 months. Applying only Ν in the soil during establishment brought adverse conditions to both grasses, Dactylis glomerata L. and Cynodon dactylon L. and to the leguminous species Mediacaco arborea L. and Τrifoliυm repens L. The crucial problem of chromium waste reclamation is therefore to ensure adequate supply of Ρ and Κ to the above leguminous species and ΝΡΚ to grasses during establishment and nitrogen in the next stages. Application of ΝΡ to seedlings of Medicaco during plantin brought good establishment and early growth.
Evaluation of foreign varieties of Gleditsia triacanthos L. in two sites of Central Macedonia, Greece
Gleditsia triacanthos L. is a leguminous tree, endemic to North America, resistant to drought and with good growth in alkaline and saline soils. Although it has many uses, its most important is the high feeding value of its fruits (pods) to domestic and wild animals which resulted in the development of several varieties. ln this research, 9 varieties-clones selected in southem France and the American ‘Millwood” were evaluated in two sites with semidry Mediterranean climate in the prefecture of Thessaloniki, northern Greece. In each site, 50 barerooted saplings, grafted a year ago on two years old wild rootstock, were planted (5 from each variety). Mortality and height measurements were taken at the end of growing season for 4 and 3 years respectively in the two sites. In the first site (Loutra Thermis) the mortality did not exceed 10% during the experimental period and the establishment was satisfactory. In the second site (Scholari), on the contrary, saplings started to get dry on the tops and mortality exceeded 26% apparently due to its sandy soils which could not support the plants especially during the first two very dry years. Height was significantly different among varieties in Loutra Thermis in the first 3 years but not in Scholari. In both sites, however, almost the same varieties ranked tallest all along thus suggesting their higher adaptation potential to the study areas. The first pods appeared in two varieties at the fourth year since grafting but in the following year the majority of them fruited. lt is concluded that Gleditsia has a great potential as a fodder tree but more selection work is needed so that the best varieties are developed for the semi-dry environments of northern Greece.